440 MW clone tuning/plug read

[miller]

Just turned 500 miles on my 64 Sport Fury. Motor is a 69 440, MW clone, with a 63 model crossram, with a pair of 1405 600 cfm Eddys.
Just pulled the plugs for a look, and a compression test, showing 150 psi all, except one 145 read.
I admit, my first 440 (like that's any dif), first crossram, first dual carbs....

Okay, what I'm looking at, on the plugs, strap mark is almost to the base. Plugs too hot? Using Champion J12YC plugs. I'll get a few pictures up, later today, after my camera gets charged.
Ceramic is tan, it's full length. One plug (#8) slightly oiled, but after finding the plug boot on the wire cooked pretty good, that is probably that problem.

Both carb mixture screws are 1 1/2 turns out. Engine runs fairly strong, pulls good, no smoke out the exhaust. What I am getting out the exhaust...is soot! At a little over 400 miles, it started showing, so during the last 100 miles, or slowly building up over time. Carb mixture too rich??

 

[Bill Monk]

http://4secondsflat.com/Spark_plug_reading.html

 

[miller]

Here's the photos...

 

[miller]

My understanding is, soot means rich mixture. Right? Might try turning mixture screws in a 1/4 turn, or maybe too much?
Carbs have the stock jets...nothing touched, except adjusting the floats.

Initial timing is 14, all in 35. Engine never has pinged, solid throttle response.

What do you guys see?

 

[Bill Monk]

Looks rich. I can't see the straps so refer to the FBO info on the timing. I use a vacuum gauge and a hand held tach for tuning. Your timing sounds about right, you might be able to take a little more depending on compression so check that first using the vacuum gauge, advance a bit more and see if the rpm and vacuum increase. Usually the highest vacuum reading is where you want to be. Check to make sure she will start there and you should be good on the timing. On the carb, turn the mixture screws in until it starts to fall down and then back out until you hit the highest RPM reading and stop. This is the tach I use for tuning, it's a multimeter with a tach function and it works great. A wideband is the best way but I still do it old school.
https://www.amazon.com/Actron-CP767...-2-spons&keywords=multimeter+automotive&psc=1

 

[oldbee]

What is ur vacuum reading at idle?

 

[Glenwood]

I found that the elec choke on my 750 eddy was set too rich and my fuel pressure was too high. Added a regulator, leaned the choke, played with the metering rod set up, timing and so on. Ran much better but then came old man winter, so never got a chance to continue tuning before I opted for a head swap.

 

[miller]

On the carb, turn the mixture screws in until it starts to fall down and then back out until you hit the highest RPM reading and stop.

That's how I've always set my mixture...but, after trying on this set-up, realized won't work on a two four carbs. Crossram manifold.

What is ur vacuum reading at idle?

Haven't messed with checking that. Suppose it will read right, hooked up to a port on just one of the carbs.

For now, putting a fresh set of J12YC plugs in it, later getting a fresh read, with mixture a little leaner. If the plug straps look the same, might look for some 11s, or even 10s, IF I can even find some. Maybe another brand.

I'll try to get a better photo of one of the plugs, later. Have to mess with a bone scan, this morning.

Appreciate you guys looking!

 

[miller]

Hmmm...4secondsflat indicates the change on the strap, near the base, says too much timing? Other charts say plug is too hot?
btw...manual chokes on the carbs, both wired open...no choke.

 

[oldbee]

Was thinking low vacuum not pulling down metering rods enuf. Maybe J-11y’s(equivalent)?

 

[Bill Monk]

That's how I've always set my mixture...but, after trying on this set-up, realized won't work on a two four carbs. Crossram manifold.


Haven't messed with checking that. Suppose it will read right, hooked up to a port on just one of the carbs.

For now, putting a fresh set of J12YC plugs in it, later getting a fresh read, with mixture a little leaner. If the plug straps look the same, might look for some 11s, or even 10s, IF I can even find some. Maybe another brand.

I'll try to get a better photo of one of the plugs, later. Have to mess with a bone scan, this morning.

Appreciate you guys looking!

As long as you connect it to a port on the throttle base, multiple carbs won't affect it, you are measuring manifold vacuum

 

[Bill Monk]

A vacuum reading will tell you a lot when setting your timing and idle mixture

 

[miller]

Appreciate all that!

Guess the blasted gas has me thrown off. Play time coming up!
Even so, kind of a kick, how strong the thing pulls, back in the seat stuff. Get my tune dialed in...

btw...compression ratio is a hair over 10:1. Mallory dual point, mechanical advance.

 

[miller]

What is ur vacuum reading at idle?

16.5" manifold pressure. Engine 'cycles' a little idling, and the vacuum reading floats between 16-17".

Still, moving the mixture screws, hardly any change up, or down. Remember, crossram with two fours, for what that's worth.

 

[oldbee]

There goes my low vac. idea. Have you tried a finger over air bleeds in the primaries! ( partially plugged?)

 

[Ski 61701]

What are your primary and secondary jet sizes? How about metering rod sizes of your carbs? Also step up spring colour? At idle the metering rods need to be sucked down not fluttering.
To aid in setting up carbs, you need a carb sync tool. Buy a carb hat from jegs or summit, then buy a motorcycle carb sync tool. Drill a hole in carb hat and fit carb sync tool on it and glue it down. Disconnect carb linkage and start car. Idle screws should be out about a quarter turn from fully seated. What you want is to put carb hat on and look to see where the idle float is, you turn the idle set screw on each carb to get the float in the same level for both carbs. Just be careful that you dont turn idle screw up to far where you uncover idle transfer slots. Set timing first before you monkey with carb adjustment. Its a little trial and error but the carb sync tool makes your life a lot easier

 

[oldbee]

Do a search for ‘Hemi cross ram idle tuning’ FBBO(2014), just found it.

 

[miller]

Hemi cross ram idle tuning’ FBBO(2014)

Yes, I've gone through that post a few times, and watched the video. Actually kinda surprised about the high RPM idle speed. Mine is 750.

What are your primary and secondary jet sizes? How about metering rod sizes of your carbs? Also step up spring colour? At idle the metering rods need to be sucked down not fluttering.

Thanks, Ski 61701! I will positively check the metering rods, to see what their doing. As mentioned, engine slightly 'cycles', until it starts warming up, then smooths out nicely.
Both Eddys are new, out of the box, with stock jets. Only things done were check, and re-adjust the floats, and operated on 'em, to swap inlet sides.

After leaning all mixture screws a 1/4 turn, went for a 100 mile drive. Soot out the pipes no more, a couple hard pulls, to get the cobwebs out. Going to pull a plug, to have a fresh look.

 

[miller]

To aid in setting up carbs, you need a carb sync tool.

Went to the website that offers the carb hats/sync tool, and read the instruction sheet. Said it was to enable getting a balanced lower idle speed...that's it? Already have mine at 750 RPM idle. Or, am I missing something. Yes, understand the balanced vacuum value.

Have the idle speed screws adjusted both the same, and mated with the linkage, so they open exactly the same.

It's the mixture settings, I'm looking at. Not sure why I'm not getting much action with a vacuum gauge, though not wanting to get too wild with my screw turning. Too lean would be a bad deal.
While I'm at it, going to do a vacuum leak check, just to be sure. And some reading in the manual...might have to look a jets.

Originally tried setting mixture with a tach, but didn't get much change there...that's why I just used a basic 1 1/2 adjustment on the mixtures. Proved too rich.

Tinker, tinker...still liking the way it runs!!

 

[miller]

At idle the metering rods need to be sucked down not fluttering.

Metering rods are firmly down at idle.